The World Health Organization (WHO) has debunked the long-held belief that dementia is an unavoidable part of ageing, saying up to 45 per cent of the risk of developing the condition can be prevented or delayed by addressing modifiable lifestyle, environmental and medical risk factors.

The global health agency disclosed this on Tuesday as it released updated Guidelines on Risk Reduction of Cognitive Decline and Dementia, saying the latest scientific evidence provides countries with practical measures to reduce the growing burden of the disease.

The announcement comes as more than 57 million people worldwide are living with dementia, while nearly 10 million new cases are diagnosed every year. Alzheimer’s disease remains the most common form of dementia, accounting for an estimated 60 to 70 per cent of all cases.

Although there is currently no cure for dementia, the WHO said nearly half of the risk is associated with factors that can be changed or effectively managed throughout life.

These include tobacco use, harmful alcohol consumption, physical inactivity, social isolation, air pollution, high blood pressure, diabetes and other noncommunicable diseases.

“We know more today than ever before about what drives dementia risk, and these guidelines translate that knowledge into action,” WHO Director-General, Dr Tedros Adhanom Ghebreyesus, said.

“Countries now have clear, evidence-based recommendations they can put into practice immediately to protect people’s cognitive health.”

According to the WHO, the updated guidance reflects significant advances in scientific evidence since the organisation first published dementia risk-reduction recommendations in 2019.

The recommendations encourage governments and healthcare providers to promote healthy behaviours across the life course, including regular physical activity, balanced diets, smoking cessation, reduced alcohol consumption and stronger social engagement.

The agency also recommends cognitive training and cognitive stimulation for adults with normal cognition or mild cognitive impairment as part of broader efforts to preserve brain health.

For the first time, the WHO has included reducing exposure to air pollution among its recommendations, citing growing evidence linking environmental factors to cognitive decline and dementia.

The guidelines also emphasise the importance of preventing and effectively managing cardiometabolic conditions such as hypertension, diabetes and high cholesterol, noting that these measures can significantly reduce dementia risk.

In addition, hearing aids may be offered as part of dementia risk-reduction strategies for people experiencing hearing loss.

However, the WHO advised against the routine use of vitamin B and E supplements, omega-3 fatty acids and multivitamins to prevent dementia in people without diagnosed nutritional deficiencies.

According to the organisation, current evidence does not demonstrate sufficient benefit from these supplements to outweigh potential harmful effects.

Beyond its impact on memory and thinking, dementia affects a person’s ability to live independently, maintain employment and perform everyday activities. The condition also places heavy emotional, physical and financial burdens on families and caregivers.

The WHO estimates that dementia costs the global economy approximately $1.3 trillion annually, with about half of that amount representing unpaid care provided by relatives and friends.

The organisation said integrating dementia prevention into existing programmes addressing noncommunicable diseases, mental health and healthy ageing could substantially reduce future cases and improve quality of life for millions of people worldwide.

Health experts say the updated recommendations reinforce growing evidence that protecting brain health begins long before old age and that early intervention remains one of the most effective strategies for reducing dementia risk.